Researchers from the University of Pennsylvania (Penn) Abramson Cancer Center have announced findings from the ADMIRAL trial of gilteritinib in patients with relapsed or refractory acute myeloid leukaemia (AML) with a mutation in the Fms-like tyrosine kinase 3 (FLT3) gene.

The study found that patients taking gilteritinib had almost double median overall survival of the chemotherapy group; 9.3 months compared to 5.6 months.

In addition, after one year of treatment, 37% of the gilteritinib group were still alive, compared to 16.7% of the chemotherapy group and 34% of the patients taking gilteritinib achieved complete remission or complete remission with partial hematologic recovery, compared to only 15% of patients given chemotherapy.

Study lead and University of Pennsylvania Perelman School of Medicine associate professor of haematology-oncology Alexander Perl said: “Across the board, this trial shows gilteritinib carries a clear survival benefit, meaning we now have a targeted, highly-effective, and well-tolerated treatment option for a group of truly high-risk patients.”

The two treatments had a similar safety profile, but Perl noted: “Although the incidence of various side effects was similar across the study arms, patients took gilteritinib for considerably longer than they underwent chemotherapy.

“This actually means the likelihood of side effects on a daily basis is lower on this drug, and this favourable side effect profile allowed us to give gilteritinib as an outpatient treatment, a huge shift for these patients.”

Gilteritinib is an inhibitor of FLT3, the most commonly mutated gene in AML patients. Normally the gene is expressed in bone marrow cells and regulates the orderly growth of

Perl continued: “This drug is specifically designed to help this group of patients, and now we’ve shown it can make a huge difference for those who, until recently, had no specific therapies available beyond chemotherapy.”

Interim data from the ADMIRAL study led to the US Food and Drug Administration to approve gilteritinib in November 2018. The drug is also being reviewed by the European Medicines Agency.

Gilteritinib is manufactured by Astellas Pharma , who funded Penn’s study, and marketed under the brand name Xospata.

The ADMIRAL trial results were presented at the 2019 American Association for Cancer Research Annual Meeting in Atlanta.